Table 2.
Characteristics and main results of clinical trials on the use of probiotics in endurance athletes and improvement of sports performance.
| Author, Year | Type of Study/Quality | Supplementation Procedure | Results | Conclusions |
|---|---|---|---|---|
| Batattinha et al., 2020 [20]. | Double-blind, placebo-controlled RCT in 27 marathon runners (men) High quality = 5 N = 11–50 |
1 sachet of Bifidobacterium-animalis-subs p.-Lactis (10 × 109 CFU) and Lactobacillus-Acidophilus (10 × 109 CFU) + 5 g maltodextrin for 30 days before the race. | The total number of CD8 T lymphocytes was maintained in the probiotic group and the production of proinflammatory cytokines decreased, enhancing the immunomodulatory role of lymphocytes. | There were no differences between the two groups in relation to URTIs. The probiotic group modulates the lymphocyte response. |
| Huang et al. 2020 [21] | Double-blind, placebo-controlled RCT in 20 triathletes (male) High quality = 5 N = 11–50. |
1 capful of Lactobacillusplantarum PS128 (1.5 × 1010CFU) for 4 weeks. | Increased endurance in the probiotic group. There were no significant differences in VO2max and body composition in the two groups. | LPS128 supplementation was associated with an improvement in endurance running performance through modulation of microbiota and related metabolites, but not in maximal oxygen uptake. |
| Lin et al. 2020 [22] | Double-blind, placebo-controlled RCT in 21 middle- and long-distance runners (7 women and 14 men) High quality = 5 N = 11–50 |
3 capsules/day for 5 weeks of Bifidobacterium longum subsp. longum Olympic No. 1 (OLP-01) (15 × 1010 CFU) after meals. | The OLP-01 group significantly increased the change in running distance of the 12-min Cooper test, with an increase in beneficial bacteria and decrease in pathogenic bacteria in the gut microbiota. | OLP-01 can be used as a sports nutrition supplement to enhance exercise performance. |
| Huang et al. 2019 [23] | Double-blind, placebo-controlled RCT in 34 triathletes. It was divided into study I (18 triathletes) and study II (16 triathletes). High quality = 5 N = 11–50 |
Study I, programmed training (triathlon preparation) and supplementation with Lactobacillus plantarum PS128 lasting 4 weeks. Study II, specialized training and supplementation with Lactobcillusplantarum PS128 lasting 3 weeks and dietary recommendations (30–40 g of carbohydrates and 500–1000 mL of water/hour) during the triathlon. |
Decrease in oxidative stress due to 6–13% decrease in proinflammatory cytokines and 55% increase in anti-inflammatory cytokines, after intense exercise. 24–69% increase in plasma amino acids and athletic performance in the probiotic group, due to improved fatigue index (FI) and maximal anaerobic power (PP). | Supplementation with Lactobacillus plantarum PS128 may be a potential ergogenic aid for better training management, physiological adaptations to exercise and health promotion. |
| Marshall et al. 2017 [24] | Double-blind RCT in 32 ultramarathoners (6 women and 26 men) High quality = 5 N = 11–50 |
Probiotic group (n = 11): 150 g/day of Lactobacillus acidophilus, bifidobacterium bifidum and bifidobacterium aniamles subspecies lactis. Probiotic + glutamine group (n = 10): 0.9 g L-glutamine per 5 g dosage. No supplementation (n = 11). Follow-up during the 12 weeks prior to the Sabre Marathon. |
After the run, eHsp72 concentrations increased by 124% (F [1,3] = 22.716, p < 0.001), indicating increased levels of systemic stress. There was no difference between groups in eHsp72 concentration. | Supplementation with probiotics or probiotics + glutamine did not decrease the concentration of eHsp72, an indicator of systemic stress after an ultramarathon. |
| Strasser et al. 2016 [25]. | Double-blind RCT in 29 ultramarathoners (16 women and 13 men) High quality = 5 N = 11–50 |
1 sachet before breakfast (1 × 1010 CFU of Bifidobacterium bifidum W23, Bifidobacterium lactis W51, Enterococcus faecium W54, Lactobacillus acidophilus W22, Lactobacillus brevis W63, and Lactococcus lactis W58), for 12 weeks. | Tryptophan levels after exercise remained unchanged in the probiotic group. The proportion of placebo who suffered 1 or 2 symptoms of URTIs increased 2.2-fold compared to the probiotic group (0.79 vs. 0.35; p= 0.02). | Daily probiotic supplementation decreased the rate of exercise-induced tryptophan degradation and reduced the incidence of URTIs, but did not benefit athletic performance, although training load was higher (h/week). |
| Jager et al. 2016 [26]. | Double-blind RCT in 15 endurance runners (male) High quality = 5 N = 11–50 |
1 capsule/day of Bifidobacterium breve BR03 and Streptococcus thermophilus FP4 (5 × 109 CFU) for 3 weeks. | Probiotic supplementation decreased circulating IL-6 up to 48 h after exercise. It improved the average peak torque in an isometric test at 24 and 72 h. | Probiotic intake mitigates performance reductions and muscle tension in the days after exercise, which damages muscles. Specific dietary probiotics can aid in performance recovery after heavy eccentric exercise, which influences the performance of endurance runners. |
| Jager et al. 2016 [27] | Double-blind RCT in 20 endurance runners (male) High quality = 5 N = 11–50 |
Cross-over study: Week 0–2, supplementation with 20 gr of casein after breakfast. Week 4–6, supplementation with Bacillus coagulans GBI-30, 6086 + 20 gr casein after breakfast. |
Probiotic + casein supplementation increased recovery at 24 and 72 h and decreased pain at 72 h, with an increase in creatine kinase (CK) of +137.7% (p = 0.001) versus casein group, which was +266.8% (p = 0.0002). In addition, muscle damage decreased (p = 0.08). Intense exercise maintained athletic performance (+10.1 watts + 1.7%). | Probiotic + casein supplementation decreased muscle damage levels, increased recovery and maintained performance after damaging exercise. |
| Gleeson et al. 2016 [28]. | Double-blind, placebo-controlled RCT in 243 collegiate athletes (women and men) High quality = 6 |
2 drinks/day (breakfast and dinner) of Lactobacillus casei shirota (6.5 × 109 CFU) for 20 weeks. | There were no significant differences in duration and severity of URTIs between groups. Significant interaction effect between times and groups against CMV1⁰ and EBV1⁰ antibodies in plasma (p < 0.01), in the probiotic group. | Probiotic supplementation did not decrease the incidence of URTIs, but decreased EBV and CMV antibodies. |
RCT: randomized clinical trial; CFU: colony-forming units; URTIs: upper respiratory tract infections; VO2max: peak oxygen volume; EBV: Epstein–Barr virus; CMV: cytomegalovirus.